1. Field of the Invention
This invention generally relates to a clutch apparatus connected to a crankshaft via an elastic member. More specifically, the present invention relates to a clutch apparatus including a clutch cover assembly axially disposed on the engine side of a clutch disk and a damper mechanism disposed between the crankshaft and the clutch cover assembly.
2. Background Information
A clutch apparatus is an apparatus that enables transmission of driving force from an engine to an input shaft of a transmission and disables the transmission of the driving force as required. The clutch apparatus basically includes a friction drive plate receiving the driving force from a crankshaft of the transmission, a clutch disk disposed adjacent to the friction drive plate, and a clutch cover assembly for urging the clutch disk against the friction drive plate and releasing the clutch disk from the friction drive plate as required. The clutch cover assembly includes a clutch cover arranged to rotate integrally with the friction drive plate, a pressure plate housed in the clutch cover adjacent to the clutch disk, and an urging member supported by the clutch cover for urging the pressure plate toward the clutch disk and the friction drive plate.
One known type of the clutch cover assembly is axially disposed on the engine side of the drive plate. In this instance, a release mechanism for releasing the clutch by applying a load to the clutch cover assembly is axially disposed on the transmission side of the friction drive plate. By way of example, the release mechanism comprises a cover member, a release member and a lever member. The cover member is secured to the axial transmission side of the friction drive plate. The release member extends through the friction drive plate and has one end forming an engaging section for engaging with the pressure plate. The lever member is levered against other end of the release member while being fulcrumed on a portion of the cover member. As the load is applied to the lever member from the drive mechanism, the lever member axially forces the release member toward the engine side while being fulcrumed on the cover member. As a result, the pressure plate overcomes the urging force of the urging member and disengages from the clutch disk. In this way, the clutch engagement is released in the clutch apparatus.
In the described prior art clutch apparatus, the clutch cover is supported, for example, at its inner peripheral end by the crankshaft or other member. Therefore, when bending vibrations are transmitted from the engine to the clutch apparatus, the entire clutch apparatus is subjected to the bending vibrations, resulting in vibrational resonances of the entire clutch apparatus.
Such clutch cover assembly may be secured to the crankshaft of the engine, for example, via a damper mechanism. A damper mechanism is disposed, for example, between the friction drive plate and a member disposed on the engine side for absorbing and reducing torque fluctuations transmitted from the engine. The damper mechanism generally includes an input side member secured to the member disposed on the engine side, an output side member secured to the clutch cover assembly, and an elastic member or springs for elastically connecting the input side member and the output side member with each other in a rotational direction. In such case, when torque fluctuations are transmitted from the engine, the springs in the damper mechanism are compressed in a rotational direction so as to absorb and reduce the torque fluctuations. Some noise and vibration problems in the drive train of the vehicle are, for example, gear-tooth noises and internal resonance noises that occur while the vehicle is running.
In order to reduce such noises and vibrations, it is necessary to minimize the torsional rigidity in the acceleration and deceleration torque ranges so as to set a torsional resonance frequency of the drive train below a practical engine speed range. In the damper mechanism, it is conceivable to increase the torsion angles of the elastic members or to arrange a plurality of elastic members operating serially in order to reduce the torsional rigidity of the damper mechanism.
On the other hand, if the elastic members have such reduced torsional rigidities, a resonance point must be passed in a low engine speed range (for example, equal to or below 500 rpm) at the engine start up and also at the engine stall. During this period, excessive torque fluctuations may occur, possibly causing damage of the damper mechanism and/or increase of the noises and vibrations. Such problems are avoided, for example, by use of one type of known lock mechanism that locks members disposed on the opposing sides of the damper mechanism while the engine speed is in the low engine speed range and unlocks these members while the engine speed is in a high engine speed range to allow operation of the damper mechanism. This lock mechanism generally includes a lock member and an elastic member. The lock member can be urged to a locking and engaging position by the elastic member to prevent relative rotation of the clutch cover assembly with respect to a member disposed on the crankshaft side and can unlock the clutch cover assembly by moving the clutch cover assembly to an unlock position with aid of centrifugal force as the engine speed reaches the high engine speed range. The use of such lock mechanism will disadvantageously results in the more complex structure and the increased number of components.
In the assembly operation of the described prior art clutch apparatus, the damper mechanism has been pre-mounted to one of the clutch apparatus and the member disposed on the engine side. In this state, when the engine is joined to the transmission, the damper mechanism must be secured to the other of the clutch apparatus and the member disposed on the engine side, for example, with bolts, rivets or the like.
Since the fastening members, such as the bolts, the rivets or the like, must be used in the assembly of the clutch apparatus, the work efficiency of the assembly operation is intrinsically low.
In view of the above, there exists a need for a clutch apparatus which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
Accordingly, one object of the present invention is to provide a clutch apparatus that is constructed to make the assembly of the clutch apparatus much easier.
Another object of the present invention is to provide a clutch apparatus that reduces the negative effects due to the bending vibrations transmitted from the engine in the clutch apparatus that has the clutch cover assembly axially disposed on the engine side of the clutch disk.
Another object of the present invention is to provide a clutch apparatus that suppresses the resonant vibrations in the low engine speed range by simplifying the structure in the clutch apparatus that connects the clutch cover assembly to the crankshaft via the damper mechanism.
In accordance with a first aspect of the present invention, there is provided a clutch apparatus for enabling and disabling transmission of driving force from a crankshaft of an engine to an input shaft of a transmission by engaging and disengaging a clutch disk, respectively. The clutch apparatus includes a clutch cover assembly for engaging and disengaging the clutch disk, and a damper mechanism for elastically connecting the clutch cover assembly to the crankshaft in a rotational direction. In this clutch apparatus, since the clutch cover is connected to the crankshaft via the damper mechanism, the structure is relatively simple in comparison to that of the prior art.
In accordance with a second aspect of the present invention, the clutch apparatus of the first aspect of the present invention has the damper mechanism including an elastic member that is retained by one of the crankshaft and the clutch cover assembly and axially releasably engages the other of the crankshaft and the clutch cover assembly. In this clutch apparatus, the damper mechanism is assembled by axially moving the crankshaft and the flywheel toward each other. That is, the clutch apparatus is easy to assemble in comparison to the prior art.
In accordance with a third aspect of the present invention, the clutch apparatus of the first and second aspects of the present invention has a clutch apparatus wherein the damper mechanism includes a disk-shaped plate member axially disposed on the engine side of a distal end of the crankshaft, the elastic member retained by the plate member at both circumferential ends and an axial transmission side thereof, and a drive member that includes an engaging section axially releasably engaging both circumferential ends of the elastic member and is secured to the crankshaft. In this clutch apparatus, the elastic member has been previously retained by the plate member prior to the assembly operation, and the engaging section of the drive member axially engages both the circumferential ends of the elastic member during the assembly operation. Therefore, the assembly is eased.
In accordance with a fourth aspect of the present invention, the clutch apparatus of the third aspect of the present invention has a clutch apparatus wherein the plate member includes a retaining section for retaining an axial engine side of the elastic member. In this clutch apparatus, the retaining section does not allow the elastic member to fall off from the plate member.
In accordance with a fifth aspect of the present invention, the clutch apparatus of the first through the fourth aspects of the present invention has a clutch apparatus that further includes a friction drive plate axially disposed on the transmission side of the clutch disk. The plate member is axially disposed on the engine side of the clutch disk and is secured to the friction drive plate.
In accordance with a sixth aspect of the present invention, the clutch apparatus of the fifth aspect of the present invention has a clutch apparatus wherein the clutch cover assembly includes a pressure plate axially disposed on the engine side of the clutch disk, and an urging member supported by the plate member for urging the pressure plate toward the clutch disk. In this clutch apparatus, the plate member provides two functions, i.e., the retaining function for retaining the elastic member as well as the supporting function for supporting the urging member, so that the number of parts is advantageously reduced.
In accordance with a seventh aspect of the present invention, the clutch apparatus of the sixth aspect of the present invention has a clutch apparatus wherein the elastic member is disposed radially inward of the pressure plate. In this clutch apparatus, since the elastic member is disposed radially inward of the pressure plate, it is possible to reduce the radial size of the entire clutch apparatus while minimizing the axial size of the entire clutch apparatus.
In accordance with an eighth aspect of the present invention, the clutch apparatus of the fifth through the seventh aspects of the present invention has a clutch apparatus wherein the plate member has an outer peripheral end secured to the friction drive plate and an inner peripheral end rotatably supported by the crankshaft.
In accordance with a ninth aspect of the present invention, the clutch apparatus of the eighth aspect of the present invention has a clutch apparatus that further includes a bearing disposed between the inner peripheral end of the plate member and the input shaft. In this clutch apparatus, the input shaft is supported by the inner peripheral end of the plate member via the bearing.
In accordance with a tenth aspect of the present invention, there is provided a clutch apparatus for enabling and disabling transmission of driving force from a crankshaft of an engine to an input shaft of a transmission by engaging and disengaging a clutch disk, respectively. The clutch apparatus includes a friction drive plate and a clutch cover assembly. The friction drive plate is axially disposed on the transmission side of the clutch disk. The clutch cover assembly includes a clutch cover axially disposed on the engine side of the friction drive plate, a pressure plate disposed adjacent to an axial engine side of the clutch disk, an urging member supported by the clutch cover for urging the pressure plate toward the friction drive plate, and an elastic member that is retained by an axial engine side of an inner peripheral section of the clutch cover and receives the driving force from the crankshaft.
In accordance with an eleventh aspect of the present invention, the clutch apparatus of the tenth aspect of the present invention has a clutch apparatus wherein the elastic member is retained by the inner peripheral section of the clutch cover and is positioned radially inward of the pressure plate. In this clutch apparatus, since the elastic member is disposed radially inward of the pressure plate, it is possible to reduce the radial size of the entire clutch apparatus while minimizing the axial size of the entire clutch apparatus.
In accordance with a twelfth aspect of the present invention, the clutch apparatus of the first through the eleventh aspects of the present invention has a clutch apparatus that further includes a mass body secured to the crankshaft. In this clutch apparatus, the mass body is directly secured to the crankshaft and does not engages the flywheel assembly or the damper mechanism. Therefore, the structure is simplified, and the entire size is reduced.
In accordance with a thirteenth aspect of the present invention, the clutch apparatus of the twelfth aspect of the present invention has a clutch apparatus wherein the mass body includes a disk-shaped member secured at its inner peripheral end to the crankshaft, and an annular member secured to an outer peripheral end of the disk-shaped member. In this clutch apparatus, since the annular member is secured to the outer peripheral end of the disk-shaped member, it is possible to reduce the axial size of the entire apparatus while maintaining the sufficient inertia.
In accordance with a fourteenth aspect of the present invention, there is provided a clutch apparatus for enabling and disabling transmission of driving force from a crankshaft of an engine to an input shaft of a transmission by engaging and disengaging a clutch disk, respectively, the clutch apparatus comprising a friction drive plate, a clutch cover assembly and a release mechanism. The friction drive plate is axially disposed on the transmission side of the clutch disk. The clutch cover assembly includes a clutch cover secured to an axial engine side of the pressure plate, a pressure plate axially disposed on the engine side of the clutch disk, and an urging member supported by the clutch cover for urging the pressure plate toward the clutch disk. The release mechanism includes a cover member that is secured to an axial transmission side of the friction drive plate and has an inner peripheral end supported by a member disposed on the transmission side, a release member having one end engaging an axial engine side surface of the pressure plate and other end disposed adjacent to the cover member, and a lever member supported by the cover member and the other end of the release member. In this clutch apparatus, the inner peripheral end of the cover member is supported by the member disposed on the transmission side. In this way, the cover member, which is the member axially disposed on the transmission side of the clutch apparatus, is advantageously supported, so that even if the bending vibrations are transmitted from the engine, the entire clutch apparatus is not readily tilted and therefore can suppress the vibrational resonances induced by the bending vibrations.
In accordance with a fifteenth aspect of the present invention, the clutch apparatus of the fourteenth aspect of the present invention has a clutch apparatus wherein the drive mechanism further includes a release bearing that has an inner race, an outer race for providing a load to the lever member and a plurality of rolling elements disposed between the inner and outer races. Furthermore, the inner peripheral end of the cover member is supported by the outer race. In this clutch apparatus, the cover member is supported by the release bearing, so that there is no need for providing a specialized support component.
In accordance with a sixteenth aspect of the present invention, the clutch apparatus of the fifteenth aspect of the present invention has a clutch apparatus that further includes a cylindrical member that is secured to the outer race and has an outer peripheral surface for axially slidably supporting an inner peripheral surface of the cover member. In this clutch apparatus, the inner peripheral surface of the cover member is supported by the cylindrical member attached to the release bearing.
In accordance with a seventeenth aspect of the present invention, the clutch apparatus of the sixteenth aspect of the present invention has a clutch apparatus wherein the cylindrical member includes a cylindrical section having the outer peripheral surface and an engaging section for engaging the lever member. In this clutch apparatus, the cylindrical member supports the inner peripheral end of the cover member and drives the lever member.
In accordance with an eighteenth aspect of the present invention, the clutch apparatus of the fourteenth through the seventeenth aspects of the present invention has a clutch apparatus wherein the clutch cover has an outer peripheral end secured to the friction drive plate and an inner peripheral end rotatably supported by the crankshaft. In this clutch apparatus, the inner peripheral end of the clutch cover is supported by the crankshaft, so that the clutch apparatus is advantageously supported by the other members on both axial sides and therefore can suppress the vibrational resonances when the bending vibrations are transmitted from the engine.
In accordance with a nineteenth aspect of the present invention, the clutch apparatus of the eighteenth aspect of the present invention has a clutch apparatus wherein the inner peripheral end of the clutch cover is radially supported by the crankshaft and also axially supported on its engine side by the crankshaft. In this clutch apparatus, the clutch cover is radially and axially positioned by the crankshaft.
In accordance with a twentieth aspect of the present invention, the clutch apparatus of the eighteenth and the nineteenth aspects of the present invention has a clutch apparatus that further includes a bearing disposed between the inner peripheral end of the clutch cover and the input shaft. In this clutch apparatus, the input shaft is supported by the inner peripheral end of the clutch cover via the bearing.
In accordance with a twenty-first aspect of the present invention, there is provided a clutch apparatus for enabling and disabling transmission of driving force from a crankshaft of an engine to an input shaft of a transmission by engaging and disengaging a clutch disk, respectively, the clutch apparatus comprising a friction drive plate, a clutch cover assembly, a damper mechanism, a damper mechanism, a release mechanism and a relative rotation limiting mechanism. The friction drive plate is axially disposed on one side of the clutch disk. The clutch cover assembly includes a clutch cover secured to the clutch disk side of the friction drive plate, a pressure plate axially disposed on the other side of the clutch disk that is opposite to the friction drive plate, and an urging member supported by the clutch cover for urging the pressure plate toward the clutch disk. The damper mechanism includes an elastic member for elastically connecting the clutch cover assembly to the crankshaft in a rotational direction. The release mechanism can move the pressure plate away from the clutch disk by applying a load to the clutch cover assembly. The relative rotation limiting mechanism is a mechanism for connecting the clutch cover assembly to a member disposed on the crankshaft side by the load applied from the release mechanism to the clutch cover assembly. In this clutch apparatus, when the clutch is released by applying the load to the clutch cover assembly from the release mechanism, the relative rotation limiting mechanism connects the clutch cover assembly to the member disposed on the crankshaft side, such as the crankshaft itself or other member secured to the crankshaft, with aid of the load. As a result, the operation of the damper mechanism is restricted when the clutch is released, so that the vibrational resonances in the low engine speed range at the engine start up or at the engine stall are suppressed. Since the locking of the damper mechanism is achieved by use of the load that is applied from the release mechanism when the clutch is released, the structure is relatively simple in comparison to that of the prior art.
In accordance with a twenty-second aspect of the present invention, the clutch apparatus of the twenty-first aspect of the present invention has a clutch apparatus wherein the release mechanism can move the pressure plate away from the clutch disk by axially applying the load to the clutch cover assembly toward the engine side. The relative rotation limiting mechanism urges the clutch cover assembly from the transmission side against the member disposed on the crankshaft side by the load axially applied from the release mechanism to the clutch cover assembly toward the engine side. In this clutch apparatus, when the release mechanism axially moves the clutch cover assembly toward the engine side, the relative rotation limiting mechanism urges the clutch cover assembly from the transmission side against the member disposed on the crankshaft side. Since the locking of the damper mechanism is achieved by use of the load that is applied from the release mechanism when the clutch is released, so that the structure is relatively simple in comparison to that of the prior art.
In accordance with a twenty-third aspect of the present invention, the clutch apparatus of the twenty-first and the twenty-second aspects of the present invention has a clutch apparatus that further includes a lock member that is secured to the crankshaft and acts as the member disposed on the crankshaft side.
In accordance with a twenty-fourth aspect of the present invention, the clutch apparatus of the twenty-third aspect of the present invention has a clutch apparatus wherein the lock member is a disk-shaped member.
In accordance with a twenty-fifth aspect of the present invention, the clutch apparatus of the twenty-fourth aspect of the present invention has a clutch apparatus wherein the clutch cover assembly is axially disposed on the engine side of the friction drive plate, and wherein a part of the clutch cover constitutes the relative rotation limiting mechanism. In this clutch apparatus, the clutch cover constitutes the relative rotation limiting mechanism and retains the spring member.
In accordance with a twenty-sixth aspect of the present invention, the clutch apparatus of the twenty-fifth aspect of the present invention has a clutch apparatus that further includes a friction member disposed between the part of the clutch cover and the member disposed on the clutch cover side. In this clutch apparatus, the clutch cover can be securely and frictionally engaged with the lock member by the friction member.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. The features of the present invention that are believed to be novel are set forth with particularity in the appended claims.